> less rambling and tangential

This is not necessarily a problem with the harness (IE, swapping from Claude Code wouldn't necessarily fix this).

If what you're looking to avoid is specifically 'rambling and tangential', you can get quite far with anything that adds directives to avoid those things, early in every context window. Ie, through use of Agents.md/claude.md, skills, hooks, and so on.

Changing model would also affect this. Fable 5, Opus 5, and Sonnet 5 are all going to average out to different levels of ramble. Openai, Xai, Google, etc; different providers models will also have different levels of ramble.

What Claude Code does take away from you is some level of control over what makes it into the context window. The system prompt which claude code append to the beginning of every session of course has measurable ramble-affect.

I quite like the Pi harness, most in part because important goal with the approach behind it is "give the user as much control over what makes it into the cotext window as possible."

Codex TUI is also good. Haven't touched it since moving to Pi however. Again- harness isnt the big "stop rambling" thing to change, tho.